Can I apply for my own patent to improve other people's products?

Qianlong Company provides references for three kinds of domestic patents: the design patent refers to a new design that is aesthetically pleasing and suitable for industrial application for the shape, pattern or combination of product and the combination of color and shape and pattern. The design patent shall be subject to the preliminary examination system, and the protection period shall be ten years, counting from the date of application. A patent for utility model refers to a new practical technical scheme for the shape, structure or combination of products. The application for a patent for utility model shall be subject to a preliminary examination system, and the protection period shall be ten years, counting from the date of application. An invention patent refers to a new technical scheme proposed for a product, method or its improvement. The application for a patent for invention shall be subject to the system of early publicity and deferred examination, and the protection period shall be twenty years, counting from the date of application.